Help, My A140 1999 is Revving itself!

[gottaluvmenatty]

Hi, I recently bought a A140 1999 reg Elegance. I have noticed sometimes (usually after the car has been left for a few hours) That the engine Revvs itself after i have started it (this lasts for 30secs to 1min maximum). I have watched the rev counter and there is definitely movement. This does not happen any other time other than immediately after starting the car. It does not rev much (up to 1000) but I cannot seem to figure out what is causing this. I have checked the accelarator pedal which doesnt seem to be sticking and the carpets are not in the way either. I have also noticed once or twice the car does not seem to accelerate well at low revs and the speed does not seem to kick in until i can manage to get up to third gear and then its fine again. i am just worried this may develop into a bigger problem and want to catch this before it gets too bad - hopefully this is something i can sort out myself. Apologies for my lack of technical knowledge, I have only had this car a month and am still getting used to it and how it all works. Any Help/Suggestions would be greatly appreciated. Thanks in Advance!